1. Field of the Invention
The present invention relates to a pressure contact terminal having pressure contact cutting edges which are formed so that a pair of pressure contact plates are projected from a pair of side plates with them facing each other.
2. Description of the Related Art
FIG. 1 shows a pressure contact terminal 1 disclosed in Japanese Patent Application Publication, Specification No. 63-23626 (1988). In this drawing, the pressure contact terminal 1 is composed of a contact section 2, a pressure contact section 3 and an electric wire holding section 4 which are formed by successively bending sheet metallic material with uniform thickness. Four pressure contact cutting edges 5, 6, 7 and 8 are formed on the pressure contact section 3 along an axial direction of a covered electric wire. These pressure contact cutting edges 5, 6, 7 and 8 are constituted so that both sides of insertion slots 9 into which the covered electric wire is inserted are cutting edge sections 10, and when the covered electric wire is press-fitted into the insertion slots 9, the covered electric wire is cut by the cutting edge sections 10. When a core wire section is connected with the cutting edge sections 10, the pressure contact terminal 1 is electrically connected with the covered electric wire.
In this pressure contact terminal 1, the insertion slots 9 of the four pressure contact cutting edges 5, 6, 7 and 8 are set so as to have different widths, namely, the pressure contact cutting edge 5 is used only for a thin electric wire, the pressure contact cutting edge 6 is used only for a thick electric wire, and the pressure contact cutting edges 7 and 8 are commonly used for thin and thick electric wires. As a result, electric wires having different sizes can be press-fitted commonly into one pressure contact terminal.
Incidentally, in the case where the widths of the insertion slots 9 of the pressure contact cutting edges are set like the above pressure contact terminal 1, for example, when the combination of the pressure contact cutting edge 5 having the insertion slot 9 with narrow width and the two pressure contact cutting edges 6 and 7 having the insertion slots 9 with width wider than that of the insertion slot 9 of the pressure contact cutting edge 5 are is used for electric wires with different sizes, the three pressure contact cutting edges 5, 6 and 7 cut into the covered portion of the thin electric wire satisfactorily. As a result, satisfactory contact can be obtained, and further a holding force of the electric wire in the axial direction can be obtained sufficiently.
However, when a thick electric wire is press-fitted into the insertion slot 9 of the pressure contact cutting edges 5, 6 and 7, the pressure contact cutting edge 5 having the narrow insertion slot 9 whittles the core wire portion of the thick electric wire, and satisfactory contact is obtained only for the two pressure contact cutting edges 6 and 7 having the wide insertion slots 9. For this reason, since the thick electric wire is press-fitted into and held at the two pressure contact cutting edges 6 and 7, the holding force in the axial direction becomes weaker, and the sufficient holding force cannot be obtained.